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Journal of Nanobiotechnology Sep 2023Calcium (Ca) is essential for mitochondrial homeostasis and function coordination, particularly in cancer cells that metabolize frequently to sustain their growth....
Calcium (Ca) is essential for mitochondrial homeostasis and function coordination, particularly in cancer cells that metabolize frequently to sustain their growth. Photochemistry mediated calcium overload has attracted lots of attention as an effective way to achieve tumor suppression. Herein, we developed a photonanomedicine to synergistically induce calcium overload via cell-surface photochemistry and thus tumor suppression. Specifically, the photosensitizer, protoporphyrin IX (PpIX) was loaded onto upconversion nanoparticles (UCNP), which was subsequently modified by a polymer bearing photo-crosslinking cinnamate (CA) groups. The resulting nanoparticle was further functionalized by anti-CD20 aptamers (Apt), to give photonanomedicine. The interaction between CD20 receptors and anti-CD20 aptamers allowed photonanomedicine to accurately attach onto the Raji cell surface after an intravenous injection. Following the local application of a 980 nm NIR laser, the photonanomedicine was able to capture the NIR light and convert it into ultraviolet (UV) light. On one hand, the converted UV light led the crosslinking of cinnamate groups in photonanomedicine, further stimulating the clustering of CD20 receptors and causing Ca influx. On the other hand, the UV light could simultaneously excited PpIX to generate reactive oxygen species (ROS) in situ to break down the integrity of cell membrane and lead to an influx of Ca. The synergistic Ca overload mediated by photonanomedicine exhibited an enhanced and superior anti-tumor efficacy. We believe this photonanomedicine expands the toolbox to manipulate intracellular Ca concentration and holds a great potential as an anti-tumor therapy.
Topics: Calcium; Photochemistry; Cell Membrane; Light; Cinnamates; Oligonucleotides
PubMed: 37726778
DOI: 10.1186/s12951-023-02090-z -
The Journal of Organic Chemistry Oct 2023An electrophilic spirocyclization of -benzylacrylamides with -halosuccinimides (NXS) as the halogenating reagents has been developed. This reaction is carried out at...
An electrophilic spirocyclization of -benzylacrylamides with -halosuccinimides (NXS) as the halogenating reagents has been developed. This reaction is carried out at room temperature under simple conditions without relying on metal reagents, photochemistry, or electrochemistry, providing a fast and efficient route to synthesize a wide variety of 4-halomethyl-2-azaspiro[4.5]decanes with satisfactory yields. The approach is further highlighted through gram-scale synthesis and diverse transformations of the spiro products.
PubMed: 37694951
DOI: 10.1021/acs.joc.3c01315 -
Nature Chemistry Oct 2023Over the past few years, evidence has accrued that demonstrates that terrestrial photochemical reactions could have provided numerous (proto)biomolecules with...
Over the past few years, evidence has accrued that demonstrates that terrestrial photochemical reactions could have provided numerous (proto)biomolecules with implications for the origin of life. This chemistry simply relies on UV light, inorganic sulfur species and hydrogen cyanide. Recently, we reported that, under the same conditions, reduced phosphorus species, such as those delivered by meteorites, can be oxidized to orthophosphate, generating thiophosphate in the process. Here we describe an investigation of the properties of thiophosphate as well as additional possible means for its formation on primitive Earth. We show that several reported prebiotic reactions, including the photoreduction of thioamides, carbonyl groups and cyanohydrins, can be markedly improved, and that tetroses and pentoses can be accessed from hydrogen cyanide through a Kiliani-Fischer-type process without progressing to higher sugars. We also demonstrate that thiophosphate allows photochemical reductive aminations, and that thiophosphate chemistry allows a plausible prebiotic synthesis of the C moieties used in extant terpene and terpenoid biosynthesis, namely dimethylallyl alcohol and isopentenyl alcohol.
Topics: Photochemistry; Sugars; Hydrogen Cyanide; Terpenes; Phosphates
PubMed: 37443293
DOI: 10.1038/s41557-023-01251-9 -
Photochemistry and Photobiology Sep 2023This article is a highlight of the paper by Huang et al. in this issue of Photochemistry and Photobiology. It describes shades of phototoxicity in fluorescent imaging...
This article is a highlight of the paper by Huang et al. in this issue of Photochemistry and Photobiology. It describes shades of phototoxicity in fluorescent imaging agents that are not intended to be phototoxic. Phototoxicity was assessed using a modified neutral red uptake (NRU) in vitro assay with mean photo-effects (MPE) for the fluorescent agents IRdye800, indocyanine green (ICG), proflavine, and methylene blue (MB), with comparisons to known phototoxic agents benzoporphyrin derivative (BPD) and rose bengal (RB). The experimental conditions were aimed to mimic clinical settings, using not only visible light, but also near-infrared light for insight to photosafety and deep tissue damage. Molecular mechanisms underlying the phototoxicities were not sought, but IRdye800 and ICG were mainly deemed to be safe, whereas proflavine and MB would require precautions since phototoxicity can overshadow their utility as fluorescent imaging agents.
PubMed: 37698338
DOI: 10.1111/php.13856 -
Chembiochem : a European Journal of... Jul 2024Curcumin is a bright yellow naturally occurring polyphenol which is the principal component of turmeric. It is used as herbal supplement, cosmetics ingredient, and food...
Curcumin is a bright yellow naturally occurring polyphenol which is the principal component of turmeric. It is used as herbal supplement, cosmetics ingredient, and food coloring agent. Over the years, the therapeutic properties of natural product curcumin have gone unexploited but not unnoticed. Curcumin cannot be employed as a drug due to limitations such as low aqueous solubility and limited bioavailability. Many attempts have been made to overcome these limitations by confining the drug in various confined media to enhance its bioavailability. The biomolecule is emissive and undergoes fundamental excited state processes such as solvation dynamics and excited state intramolecular proton transfer (ESIPT). Curcumin based biomaterials and nanomaterials are also a fast advancing field where curcumin is an intrinsic component necessary for formation of these materials and no longer added as an external free drug. In this review, we will summarise the recent research on the photophysical and photochemical properties of curcumin and its excited state dynamics in various bio-mimicking systems. At the same time we wish to also incorporate the various applications of curcumin, especially in biology. Lastly due to the growing importance of materials science, we will briefly discuss some recent advances on curcumin based biomaterials and nanomaterials.
PubMed: 38954727
DOI: 10.1002/cbic.202400335 -
Photochemical & Photobiological... Apr 2024Photochemistry of the (n-BuN)[Pt(NO)] complex in acetonitrile was studied by means of stationary photolysis and nanosecond laser flash photolysis. The primary...
Photochemistry of the (n-BuN)[Pt(NO)] complex in acetonitrile was studied by means of stationary photolysis and nanosecond laser flash photolysis. The primary photochemical process was found to be an intramolecular electron transfer followed by an escape of an NO radical to the solution bulk. The spectra of two successive Pt(III) intermediates were detected in the microsecond time domain, and their spectral and kinetic characteristics were determined. These intermediates were identified as Pt(NO) and Pt(NO) complexes. Disproportionation of Pt(III) species resulted in formation of final Pt(II) products.
PubMed: 38430371
DOI: 10.1007/s43630-024-00550-5 -
Angewandte Chemie (International Ed. in... Nov 2023Polystyrene (PS) particles were synthesized in ethanol/water mixture by dispersion polymerization using visible light irradiation, with either a N-heterocyclic carbene...
Polystyrene (PS) particles were synthesized in ethanol/water mixture by dispersion polymerization using visible light irradiation, with either a N-heterocyclic carbene borane-based photoinitiating system (PIS) or a disulfide. With the full PIS and poly(ethylene glycol) methyl ether methacrylate (PEGMA) as stabilizer, the size distributions were broad and the amount of PEGMA had a strong impact on the experiment reproducibility. The addition of a base solved the problem, leading to faster polymerizations, narrower size distributions and larger particles. With the disulfide as sole PIS, bigger and narrowly distributed PS particles were again formed. Quantitative conversion was achieved in each system, with particle size ranging between 100 and 350 nm. The use of poly(N-vinylpyrrolidone) as stabilizer led to significantly larger particles, up to 1.2 μm, with narrow size distributions. The production of such large latex particles by photoinitiated polymerizations is unprecedented.
PubMed: 37747841
DOI: 10.1002/anie.202309674 -
Organic & Biomolecular Chemistry Dec 2023Photochemistry provides an important platform for the discovery of synthetically useful transformations. The development of new oxidative photoreactions, however, has... (Review)
Review
Photochemistry provides an important platform for the discovery of synthetically useful transformations. The development of new oxidative photoreactions, however, has proven to be relatively challenging. The importance of the identity of the terminal oxidant has been an underappreciated consideration in the design of these reactions. Many of the most common terminal oxidants used in ground-state catalytic methods are poorly compatible with the one-electron oxidation state changes characteristic of photoredox reactions and result in hard-to-control deleterious side reactions. As an alternative, Cu(II) salts have emerged as versatile terminal oxidants in photochemical oxidation reactions that are terrestrially abundant, cost-effective, and readily compatible with one-electron oxidation state changes. This review highlights recent reaction methods that leverage Cu(II) oxidation in combination with the photochemical activation of substrates or that use Cu(II) salts as both the active chromophore and terminal oxidant.
PubMed: 38047405
DOI: 10.1039/d3ob01678a -
Journal of Materials Chemistry. B Jan 2024Bacteriorhodopsin is a biological material with excellent photosensitivity properties. It can directly convert optical signals into electrical signals and is widely used...
Bacteriorhodopsin is a biological material with excellent photosensitivity properties. It can directly convert optical signals into electrical signals and is widely used in various biosensors. Here, we present a bR-based wearable pH biometer that can be used to monitor wound infection. The mechanism of the pH-sensitive effect of the bR electrode is explained, which generates a transient photovoltage under light irradiation and a negative photovoltage when the lamp is turned off. Since the photoelectric signal of bR is affected by different pH values, the photovoltage is changed by adjusting the pH value. The ratio (/) of negative photovoltage () to positive photovoltage () has a good linear relationship ( = 0.9911) in the pH range of 4.0-10.0. experiments using rats as a model confirmed that this wearable pH biometer can monitor pH changes that occur in wound infection.
Topics: Animals; Rats; Photochemistry; Hydrogen-Ion Concentration; Bacteriorhodopsins; Wound Infection; Wearable Electronic Devices
PubMed: 38229580
DOI: 10.1039/d3tb02466k -
Scientific Reports Jul 2023We have analyzed the effect of salinity on photosystem II (PSII) photochemistry and plastoquinone (PQ) pool in halophytic Mesembryanthemum crystallinum plants. Under...
We have analyzed the effect of salinity on photosystem II (PSII) photochemistry and plastoquinone (PQ) pool in halophytic Mesembryanthemum crystallinum plants. Under prolonged salinity conditions (7 or 10 days of 0.4 M NaCl treatment) we noted an enlarged pool of open PSII reaction centers and increased energy conservation efficiency, as envisaged by parameters of the fast and slow kinetics of chlorophyll a fluorescence. Measurements of oxygen evolution, using 2,6-dichloro-1,4-benzoquinone as an electron acceptor, showed stimulation of the PSII activity due to salinity. In salt-acclimated plants (10 days of NaCl treatment), the improved PSII performance was associated with an increase in the size of the photochemically active PQ pool and the extent of its reduction. This was accompanied by a rise in the NADP/NADPH ratio. The presented data suggest that a redistribution of PQ molecules between photochemically active and non-active fractions and a change of the redox state of the photochemically active PQ pool indicate and regulate the acclimation of the photosynthetic apparatus to salinity.
Topics: Plastoquinone; Salt-Tolerant Plants; Mesembryanthemum; Chlorophyll A; Salinity; Sodium Chloride; Oxidation-Reduction; NADP; Photosystem II Protein Complex
PubMed: 37430104
DOI: 10.1038/s41598-023-38194-7